| This tele-extender is for use with Celestron 5" to 14" catadioptric telescopes only, using the Celestron 1.25" visual back (eyepiece/star diagonal holder) supplied with those scopes. It can be used with 8" to 16” Meade catadioptrics, but only if you add an optional Celestron visual back #9125, as the standard equipment Meade visual back is not physically compatible with the Celestron tele-extender. An eyepiece is inserted into the visual back and secured firmly in place with the thumbscrew in the visual back. (Current Celestron visual backs have two thumbscrews for extra security when holding CCD cameras, etc., and one must be removed before using the tele-extender.) The tele-extender is slipped over the eyepiece/visual back combination. Two thumbscrews in the tele-extender clamp down on the body of the visual back to hold the tele-extender and camera in place. A rectangular metal safety shield on the tele-extender body fits over the visual back thumbscrew to prevent accidental loosening of the thumbscrew while in use. The wide body of the deluxe tele-extender allows it to be used with oversized 1.25" eyepieces up to 1.65" outer diameter (this includes all Celestron 1.25” eyepieces except 35mm and 42mm Ultimas, all TeleVue and Meade Plössls shorter than 26mm, etc.) This gives extra flexibility in the choice of eyepieces. However, since the tele-extender is held in place by two thumbscrews instead of being screwed directly onto the visual back, extra care must be taken to tighten the thumbscrews securely to prevent the tele-extender and camera from detaching from the telescope. The tele-extender has internal antireflection threading for high contrast. Needs optional T-ring. |